JP2019096770A - Circuit structure - Google Patents

Abstract

To provide a circuit structure capable of performing heat dissipation without increasing a fin volume.SOLUTION: A circuit structure 1 includes a circuit unit 10 supported by a support member 20. The support member 20 includes: a heat radiating unit 22 projecting outward from an opposite surface to a support surface that supports the circuit unit 10; and a leg 23 which is formed to extend more than a height of a protrusion of the heat radiating unit 22. Thus, heat can be dissipated without increasing a fin volume.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit assembly.

  A circuit configuration in which a conductive member (also referred to as a bus bar or the like) constituting a circuit for conducting a relatively large current is fixed to a substrate on which a conductive pattern constituting the circuit for conducting a relatively small current is formed. The body is generally known (see, for example, Patent Document 1). In such a circuit structure, for example, heat is dissipated to the outside through a heat sink after the soaking with a bus bar.

JP 2003-164039 A

  However, when it is necessary to provide an attachment site on the heat sink side of the circuit assembly, it is difficult to secure an escape path for air, so it is necessary to increase the fin volume for heat radiation, resulting in cost and weight It has the problem of increasing.

  An object of the present invention is to provide a circuit structure capable of performing heat dissipation without increasing the fin volume.

  The circuit structure according to an aspect of the present invention is a circuit structure having a circuit portion supported by a support member, and the support member protrudes outward from the opposite surface of the support surface that supports the circuit portion. And a leg portion which is formed to extend more than the projecting height of the heat radiating portion.

  According to the above, heat dissipation can be implemented without increasing the fin volume.

FIG. 1 is a front view of a circuit assembly according to Embodiment 1; It is a top view of a circuit structure. It is a bottom view of a circuit composition. It is a perspective view of a circuit structure. It is the elements on larger scale of the connection part which connects a leg part and a radiation fin. It is a schematic explanatory drawing explaining the attachment state of a circuit structure. It is a schematic explanatory drawing explaining the flow of the air in a thermal radiation part. It is an explanatory view explaining a flow of air in a comparative example. FIG. 7 is a bottom view of a circuit assembly according to Embodiment 2;

  Embodiments of the present invention will be listed and described. In addition, at least a part of the embodiments described below may be arbitrarily combined.

  The circuit assembly according to one aspect of the present invention is a circuit assembly including a circuit unit supported by a support member, and the support member protrudes outward from the opposite surface of the support surface that supports the circuit unit. And a leg portion which is formed to extend more than the projecting height of the heat radiating portion.

  In this aspect, since the leg portion is formed to extend more than the protruding height of the heat radiating portion, the lower end surface of the heat radiating portion and the portion to be mounted when the circuit structure is attached to the mounting site via the leg portion. A gap is created between the mounting site. That is, since a space is formed between the heat radiating portion and the mounting portion, the flow of air is not blocked by the heat radiating portion, and a decrease in the heat radiating performance can be avoided.

  In the circuit structure according to one aspect of the present invention, the heat dissipation portions extend in a first direction in the surface of the opposite surface, and are juxtaposed at intervals in a second direction intersecting the first direction. A plurality of heat radiation fins, wherein the leg portion is provided apart from the heat radiation portion in the first direction, and the leg portion and one of the heat radiation fins are connected by a connection portion.

  In this aspect, since the leg portion and one of the heat dissipating fins provided in the heat dissipating portion are connected via the connecting portion, the strength of each leg portion can be increased. As a result, even when the circuit assembly is attached to a mounting site such as a vehicle, it is possible to avoid damage or the like of the leg portion caused by the vehicle vibration.

  In the circuit assembly according to one aspect of the present invention, the leg portion is a mounting plate attached to the mounting site, and two side plates which are provided upright on the mounting plate and are spaced apart in the second direction. And the connection part includes two connection plates which are obliquely connected to the heat dissipating fins connected to the leg parts and separately connected to the two side plates.

  In this aspect, when the circuit assembly is attached to the mounting site so that the space formed between the two adjacent heat radiation fins extends in the substantially vertical direction, the air warmed by the heat radiation from the heat radiation fins is , Vertically upward through the space between the heat dissipating fins. In addition, the air that has flowed vertically upward between the heat radiation fins is led to the outside of the circuit component by the slopes of the connection plate. Therefore, in this aspect, the heat generated in the circuit portion can be efficiently dissipated to the outside through the space between the heat dissipating fins, and good heat dissipating performance can be secured.

  The circuit structure according to an aspect of the present invention includes two of the legs, one of the two legs being connected to one heat radiation fin at one end side in the first direction, and the other is The other heat radiation fin is connected to the other heat radiation fin at the other end side in the first direction.

  In this aspect, because the mounting portion is attached using the two legs provided at intervals in the left and right direction and the front and rear direction of the base, the weight of the circuit structure can be reduced while securing the mounting strength. be able to.

  The circuit assembly according to an aspect of the present invention further includes a leg connected to the one radiation fin at the other end side in the first direction.

  In this aspect, since attachment is performed to the attachment site using three legs provided at intervals in the left-right direction and the front-rear direction of the base, attachment strength can be secured.

Hereinafter, the present invention will be specifically described based on the drawings showing the embodiments thereof.
Embodiment 1
1 is a front view of a circuit assembly 1 according to the first embodiment, FIG. 2 is a plan view thereof, FIG. 3 is a bottom view thereof, and FIG. 4 is a perspective view thereof. The circuit assembly 1 constitutes an electric connection box disposed in a power supply path between a power source such as a battery provided in a vehicle and a load including an on-vehicle electrical component such as a lamp or a wiper or a motor. The circuit structure 1 is used as an electrical component such as a DC-DC converter or an inverter.

  The posture in the case where the circuit assembly 1 is attached to the attachment site C (see FIG. 6) such as a vehicle will be described later, but in the first embodiment, it is illustrated for convenience in FIGS. The “front”, “rear”, “left”, “right”, “upper”, and “lower” of the circuit assembly 1 are defined according to the front, rear, left, right, upper and lower directions. Below, the structure of the circuit structure 1 is demonstrated using each direction of front and rear, right and left, and the upper and lower sides defined by FIGS. 1-4.

  The circuit assembly 1 includes a circuit unit 10 and a support member 20 for supporting the circuit unit 10. The circuit unit 10 includes a circuit board having a circuit pattern, a bus bar configuring the power circuit, an electronic component (not shown) mounted on the circuit board, and the bus bar. The electronic component is appropriately mounted in accordance with the application of the circuit assembly 1 and includes a switching element such as a field effect transistor (FET), a resistor, a coil, a capacitor, and the like.

  The support member 20 has a base 21 having a support surface 211 for supporting the circuit unit 10 on the upper surface, a heat release unit 22 provided on the surface (lower surface 212) opposite to the support surface 211, and the heat release unit 22. It has legs 23A-23C provided on the left and right ends of the base 21. The base 21, the heat radiating portion 22, and the legs 23 </ b> A to 23 </ b> C included in the support member 20 are integrally formed by die casting using a metal material such as aluminum or aluminum alloy, for example.

  The base 21 is a rectangular flat plate member having an appropriate thickness. The base 21 has, for example, dimensions of about 120 mm in the left-right direction and about 80 mm in the front-rear direction. The circuit structure 1 is fixed to the support surface 211 of the base 21 by a known method such as bonding, screwing, or soldering.

  The heat radiating portion 22 includes a plurality of heat radiating fins 221 a to 221 g protruding downward from the lower surface 212 of the base 21, and radiates the heat generated from the circuit unit 10 to the outside. The radiation fins 221a to 221g extend in the left-right direction, and are arranged in parallel at intervals in the front-rear direction. Each of the heat radiation fins 221a to 221g is a rectangular plate-like member having a size of about 90 to 100 mm in the left-right direction, a size (projecting height) of about 20 mm in the up-down direction, and a thickness of about 3 mm. The cross-sectional shape in the thickness direction (front-rear direction) of the heat radiation fins 221a to 221g has, for example, an elongated mountain shape which is elongated in the vertical direction in which the lower end portion is formed in a tapered shape.

The legs 23A to 23C are provided at the left and right ends of the base 21. In the present embodiment, two legs 23A and 23B are provided on the right side of the base 21 and one leg 23C is provided on the left side. The leg portions 23A to 23C are disposed substantially in parallel with the lower surface 212 of the base 21 and attached to the attachment portion C of the vehicle or the like, and a pair of front and rear ends rising from the attachment plate 231 and continuing to the lower surface 212 of the base 21 Side plates 232a and 232b are provided. Further, the leg portions 23A to 23C are provided with a reinforcing plate 233 which is disposed to intersect the side plates 232a and 232b and which is continuous with both the mounting plate 231 and the side plates 232a and 232b.
In the following description, the legs 23A to 23C at the left and right ends are also simply described as the legs 23 when it is not necessary to distinguish them.

  Each leg portion 23 is formed to extend more than the protruding height of the heat dissipation portion 22. That is, the separation distance from the lower surface 212 of the base 21 to the lower surface of the mounting plate 231 of each leg 23 is the separation distance from the lower surface 212 of the base 21 to the lower end surfaces of the radiation fins 221a to 221g (ie, the radiation fins 221a to 221g). The height dimensions of each leg 23 and the radiation fins 221a to 221g are designed to be slightly longer than the protruding height).

  The mounting plate 231 of each leg 23 is provided with a bolt insertion hole 234. The bolt insertion hole 234 is a through hole that penetrates the mounting plate 231 in the thickness direction, and has a diameter slightly larger than a bolt to be inserted. The leg portion 23 is configured to be attached to a mounting site C of a vehicle or the like using a bolt inserted into the bolt insertion hole 234.

  Each leg 23 is connected to one of the heat radiation fins 221 a to 221 g provided in the heat radiation unit 22. In the example shown in FIG. 3, one leg 23 (23A) on the right side is connected to the right end of the second heat radiation fin 221b from the front side among the plurality of heat radiation fins 221a to 221g provided in the heat radiation unit 22. The other right leg 23 (23B) is connected to the right end of the second radiation fin 221f from the rear side. In the left leg 23 (23C), the second heat radiation fin 221f from the rear side (that is, the other leg 23 on the right side) of the plurality of heat radiation fins 221a to 221g included in the heat radiation unit 22 is connected It is connected with the left end of the radiation fin 221f).

  As described above, by connecting each leg portion 23 and the heat radiation fin 221 b (or 221 f) through the connection portion 24, the strength of each leg portion 23 can be enhanced. Even when the circuit assembly 1 is attached, breakage or the like of the leg 23 caused by vehicle vibration can be avoided.

  FIG. 5 is a partially enlarged view of the connecting portion 24 connecting the leg portion 23 and the radiation fin 221b. The connection portion 24 includes two connection plates 241 a and 241 b that are branched from the end in the extending direction (left and right direction) of the heat radiation fin 221 b and are connected to two side plates 232 a and 232 b included in the leg portion 23. The connection plates 241a and 241b are disposed in an oblique direction with respect to the direction in which the heat dissipating fins 221b extend. An angle θ1 between the extension line L extending the radiation fin 221b and the direction in which the one connection plate 241a is disposed is an angle less than 90 degrees. In addition, an angle θ2 between the extension line L extending the radiation fin 221b and the direction in which the other connection plate 241b is disposed is also an angle less than 90 degrees. Here, the angles θ1 and θ2 may be angles of the same size, or may be angles of different sizes.

Hereinafter, the operation of the circuit assembly 1 according to the present embodiment will be described.
FIG. 6 is a schematic explanatory view for explaining the mounting state of the circuit structure 1. The circuit configuration body 1 is attached to the mounting site C such that the extending direction of the radiation fins 221a to 221g is substantially vertical. That is, the circuit assembly 1 is attached such that the space formed between the two adjacent heat radiation fins extends in the substantially vertical direction. Thus, when the circuit assembly 1 is attached, the heat generated from the circuit unit 10 is dissipated by the radiation fins 221a to 221g, and the air warmed by the radiation from the radiation fins 221a to 221g is the radiation fins 221a to 221g. Flow vertically upward through the space between Moreover, the air which flowed vertically upwards between radiation fin 221a-221g is guide | induced to the exterior of the circuit structure 1 by the slope of connection board 241a, 241b. Therefore, in the circuit configuration body 1 according to the present embodiment, the heat generated in the circuit unit 10 can be efficiently dissipated to the outside through the space between the heat radiation fins 221a to 221g, and good heat radiation performance is ensured. Can.

  Further, in the present embodiment, each leg 23 is formed to extend more than the protruding height of the heat dissipation portion 22, so when the circuit structure 1 is attached to the mounting site C via the leg 23 A clearance is generated between the lower end surfaces of the heat radiation fins 221 a to 221 g and the attachment site C. That is, since a space is formed between the radiation fins 221a to 221g and the mounting site C, the flow of air is not blocked by the radiation fins 221a to 221g, and a decrease in the radiation performance can be avoided. .

  FIG. 7 is a schematic explanatory view for explaining the flow of air in the heat radiating portion 22, and FIG. 8 is an explanatory view for explaining the flow of air in the comparative example. In the comparative example shown in FIG. 8, the connecting portion 34 between the heat dissipating fin 321 and the leg portion 33 has an orthogonal portion 341 orthogonal to the extending direction of the heat dissipating fin 321. In this case, although the air warmed by the heat radiation from the radiation fin 321 flows vertically upward through the space between the radiation fins 321, the flow of the air is blocked by the orthogonal portion 341, so the warmed air Will stay near the orthogonal part, and the heat radiation effect will be reduced.

  On the other hand, in the circuit structure 1 according to the present embodiment, as described above, the air warmed by the heat radiation from the radiation fins 221a to 221g passes vertically through the space between the radiation fins 221a to 221g. And flows to the outside of the circuit component 1 by the slopes of the connection plates 241a and 241b. Therefore, the flow of air vertically upward is not blocked by the connecting plates 241 a and 241 b of the connecting portion 24, and the warmed air does not stay near the connecting portion 24, so heat is efficiently dissipated. Can.

  As described above, in the present embodiment, since the leg portion 23 is connected to the radiation fin 221 b (221 f) via the connection portion 24, the strength of the leg portion 23 can be increased. Further, in the present embodiment, the leg portion 23 of the support member 20 is formed to extend beyond the protruding height of the heat radiation fins 221a to 221g, and a connecting portion for connecting the leg portion 23 and the heat radiation fins 221b (221f) The 24 connection plates 241a and 241b are arranged in a direction oblique to the direction in which the heat radiation fins 221b (221f) extend. Therefore, when the circuit assembly 1 is attached to the mounting site C so that the extending direction of the radiation fins 221a to 221g is substantially vertical, the flow of air may not be blocked by the radiation fins 221a to 221g or the connecting portion 24. Instead, the air warmed by the heat radiation from the heat radiation fins 221a to 221g can be efficiently released to the outside of the circuit configuration body 1.

Second Embodiment
In the first embodiment, two legs 23A and 23B are provided at the right end of the base 21 and one leg 23C is provided at the left end of the base 21, but one leg 23 is provided at each of the left and right ends of the base 21. It is good also as composition.
In the second embodiment, a configuration in which one leg 23 is provided on each of the left and right ends of the base 21 will be described.

  FIG. 9 is a bottom view of the circuit structure 1 according to the second embodiment. The circuit assembly 1 according to the second embodiment includes a circuit unit 10 (see FIG. 1 and the like) and a support member 20 for supporting the circuit unit 10. The configuration of the circuit unit 10 is the same as that of the first embodiment, and includes a circuit board having a circuit pattern, a bus bar configuring a power circuit, an electronic component (not shown) mounted on the circuit board and the bus bar.

  The support member 20 has a base 21 having a support surface 211 for supporting the circuit unit 10 on the upper surface, a heat release unit 22 provided on the surface (lower surface 212) opposite to the support surface 211, and the heat release unit 22. It has legs 23A and 23C provided on the left and right ends of the base 21. The base 21, the heat radiating portion 22, and the legs 23A and 23C included in the support member 20 are integrally formed by die-casting using a metal material such as aluminum or an aluminum alloy, for example.

  The configurations of the base portion 21 and the heat radiating portion 22 of the support member 20 are the same as in the first embodiment, and the description thereof will be omitted.

The legs 23A and 23C are provided at the left and right ends of the base 21. In the present embodiment, the leg portion 23A is provided on the right side of the base portion 21, and the leg portion 23C is provided on the left side of the base portion 21. In the example shown in FIG. 9, the leg 23A on the right side is connected to the right end of the second heat radiation fin 221b from the front side through the coupling part 24 among the plurality of heat radiation fins 221a to 221g of the heat radiation unit 22 The left leg 23C is connected to the left end of the second heat dissipating fin 221f from the rear side via the connecting portion 24.
In the following description, the legs 23A and 23B at the left and right ends are also simply described as the legs 23 when it is not necessary to distinguish them.

  Each leg 23 is disposed substantially parallel to the lower surface 212 of the base 21 and attached to the attachment portion C of the vehicle or the like, and a pair of front and rear side plates which stand up from the attachment plate 231 and continue to the lower surface 212 of the base 21 232a and 232b (see FIG. 4 and the like). Each leg 23 is provided with a reinforcing plate 233 (see FIG. 4 and the like) which is disposed to intersect with the side plates 232a and 232b and is continuous with both the mounting plate 231 and the side plates 232a and 232b. The bolt insertion hole 234 is provided in the attachment plate 231 of each leg portion 23 so that the leg portion 23 is attached to a mounting site C such as a vehicle using a bolt inserted into the bolt insertion hole 234. It is configured. In addition, attachment of the circuit structure 1 to the attachment site | part C is attached to the attachment site | part C so that the extension direction of radiation fin 221a-221g may turn into a substantially perpendicular direction.

  As described above, in the second embodiment, since the leg portion 23 provided at an interval in the left and right direction and the front and rear direction of the base 21 is attached to the attachment site C, the attachment strength can be secured. . When the circuit assembly 1 is attached to the mounting site C so that the extending direction of the radiation fins 221a to 221g is substantially vertical, part of the air warmed by the radiation from the radiation fins 221a to 221g is A part of the air that is led to the outside of the circuit component 1 by the slopes of the connection plates 241a and 241b and warmed is directly outside the circuit component 1 without passing through the slopes of the connection plates 241a and 241b. Because it is led to, you can efficiently release the heat.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is indicated not by the meaning described above but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

  For example, in the present embodiment, the configuration of the heat dissipation portion 22 provided with seven heat dissipation fins 221a to 221g has been described, but the number of heat dissipation fins is not limited to seven. The number of heat dissipating fins may be appropriately designed according to the required heat dissipating performance, and may be 6 or less, or 8 or more.

  Further, the dimensions of the support member 20 and the heat radiation fins 221a to 221g can be appropriately designed according to the specification of the circuit structure 1, the required heat radiation performance, and the like, and are limited to the dimensions described in the above embodiment. It is not something to be done.

  Furthermore, in the present embodiment, the radiation fins 221a to 221g are disposed along the long side direction of the base 21 and a plurality of the fins are arranged in the short side direction. However, along the short side direction of the base 21 The radiation fins 221a to 221g may be disposed, and a plurality of the fins may be disposed in parallel in the long side direction.

  Furthermore, although the circuit structure 1 includes two or more legs 23 in the actual mode, the number of the legs 23 may be one as long as the mounting strength can be secured.

DESCRIPTION OF SYMBOLS 1 Circuit composition 10 Circuit part 20 Support member 21 Base 22 Heat dissipation part 23 (23A-23C) Leg part 24 Connection part 211 Support surface 212 Lower surface 221a-221g Heat dissipation fin 231 Mounting plate 232a, 232b Side plate 233 Reinforcing plate 233
234 Bolt insertion holes 241a, 241b Connection plate L Extension line C Mounting site

Claims (5)

A circuit assembly comprising a circuit portion supported by a support member, the circuit structure comprising:
The support member is
A heat dissipating portion projecting outward from the opposite surface of the support surface supporting the circuit portion;
And a leg portion which is formed to extend more than the projecting height of the heat radiating portion. The heat dissipating portion includes a plurality of heat dissipating fins extending along a first direction in the surface of the opposite surface and spaced apart in a second direction intersecting the first direction.
The leg portion is provided apart from the heat dissipation portion in the first direction,
The circuit structure according to claim 1, wherein the leg portion and one of the heat dissipating fins are connected by a connecting portion. The legs are
A mounting plate attached to the mounting site,
And two side plates disposed upright on the mounting plate and spaced apart in the second direction;
The connecting portion is
The circuit assembly according to claim 2, further comprising: two connecting plates that are obliquely connected to the heat dissipating fins connected to the legs and are separately connected to the two side plates. Equipped with two of the legs,
One of the two legs is connected to one radiation fin at one end in the first direction, and the other is connected to the other radiation fin at the other end in the first direction. The circuit structure according to claim 2 or claim 3. The circuit structure according to claim 4, further comprising: a leg connected to the one radiation fin at the other end side of the first direction.

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